Subscriber unit and method for extended communication

ABSTRACT

The present invention relates to a subscriber unit in a home environment and a communication system. In one embodiment the subscriber unit has an input for connection to a local video signal, from for instance a picture telephone or a video camera. A video/picture signal may thereby be reproduced in a TV-receiver being connected to the subscriber unit. A sensor in the subscriber unit detects whether a local video signal is present on the telephone unit&#39;s input. If this is the case, the control unit connects this signal to the receiving means for further transmission through the subscriber unit and the TV-receiver. The picture telephone image may either be shown separately across the entire screen of the TV or be presented in parallel with other pictorial/video information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending U.S. patent applicationSer. No. 15/901,804 filed on Feb. 21, 2018, which claims the benefit ofthe filing date and priority to U.S. patent application Ser. No.12/987,081, filed on Jan. 7, 2011, which claims the benefit of thefiling date and priority to U.S. patent application Ser. No. 12/349,842,filed on Jan. 7, 2009, which claims the benefit of the filing date andpriority to U.S. patent application Ser. No. 10/148,389, filed on May31, 2002, which claims the benefit of the filing date and priority toInternational Application No. PCT/SE00/02406 filed on Dec. 1, 2000,which claims the benefit of the filing date and priority to SwedishApplication No. 9904360-6 filed on Dec. 1, 1999. All of the aboveapplications are incorporated by reference in their entirety.

THE BACKGROUND OF THE INVENTION AND PRIOR ART

The present invention relates to an arrangement for transmission ofsignal units to at least one receiver.

As far as, for instance, TV-signals are concerned, these may reachviewers via terrestrial transmitters, cable networks or satellites. Eachtransmitted TV-channel comprises an image signal, a so-called videosignal and one or more sound signals, so-called audio signals andusually a text-TV-signal. All signals are modulated onto a carrier wave.The TV-receiver, which is connected to the TV receiver antenna receivesthe signals. The channel selector in the TV-receiver, i.e. the unit forchannel tuning in the TV-receiver, tunes into a desired TV-channel,where after the signals are detected, i.e. demodulated. The sound signalis fed to the speaker for acoustic reproduction and the image signal isfed to a decoder where after the image reproduction can take place.

For instance, cable TV-transmissions are encrypted, i.e. the respectivesignals characteristics is altered, with the aim of preventingunauthorised viewing, i.e. preventing image- and sound reproduction ofpay-TV-channels for which no payment has been made. In order to receivesuch signal and reproduce it in a satisfactory manner the TV-receivermay include means, such as a separate decoder being arranged to decryptthe respective encrypted signal to its original characteristics whereafter image- and sound reproduction can take place in a satisfactorymanner.

However, such decoder may be manipulated, whereby the image- and soundreproduction can take place in a satisfactory manner without a userhaving paid for the TV-channel in question.

Different transmission- and reception systems for encrypted TV-signalsare known which are arranged to render unauthorised image- and soundreproduction more difficult.

EP, A2, 0 489 385 discloses one such system. The signals are encryptedin such manner that they cannot be received and decrypted by means of aregular TV-receiver, but only by means of a receiver that includes anadapted decoder, which includes a control circuit that periodicallyreceives a secret code from a central computer via a telephone line,whereby the secret code is necessary for the decryption operation. Thesecret code is sent according to an encrypted format and at irregulartime intervals. Furthermore, the secret code is altered with the aim atensuring the system's security. The secret code is transmitted to theuser under the condition that he/she has paid for a particular channel,for instance, during a previous payment period. The international patentapplication WO, Al, 97/23996 describes a method and an apparatus forselection of programs and channels according to a specific user'spreferences with respect to, for instance, avoidance of certain programtypes or specific programs. Alternatively, the user may choose only tohave particularly offensive or objectionable portions in the programsthat are transmitted to his/her receiver blocked or substituted byalternative sound- or audio sequences. The setting of the selectionfunction is exclusively effected locally at the particular userlocation. The user thus has full freedom to determine what should beblocked and what should be allowed through.

SUMMARY OF THE INVENTION

The object of the present invention is to provide an arrangement bymeans of which it is possible to block specific signals, such as certainTV-signals, from a central computer, such that the signals never reach auser's TV-receiver. Hence, the signals will not have to be encryptedwith the aim at preventing unauthorised sound- and image reproduction.This is achieved by providing apparatus/system according to the claims.

This object is achieved by the initially arrangement described thatcomprises a receiving means being arranged to receive a number of signalunits within a frequency range, whereby each signal unit includes atleast one signal, and a forwarding means is arranged to make possiblefor at least a portion of said signal units to be forwarded or at leastpartially be blocked with respect to said receiver. The arrangement isthus intended to be arranged between a receiver antenna and saidreceiver. According to the invention, it is thereby possible toexclusively allow those signal units to pass the arrangement that saidreceiver, for instance a TV-receiver, has authorised access to.

The signal units that are received by the receiving means have usuallybeen passed through some kind of signal processing and been modulatedaccording to some kind of modulation method. However, the receivingmeans that comprises a receiver includes the equipment necessary todemodulate the signal units to baseband. The arrangement may eitherprocess the signal units as analogue signal units or as digital signalunits. The transmitted signal units may have been sent via telephoneline, a coaxial cable, a radio connection, a satellite channel, a radiorelay system, fibre optics or a combination of some of these physicalmedia.

The arrangement also comprises a registering means, which in turnincludes a register over at least those signal units to which saidreceiver has authorised access. The forwarding means is thereby arrangedto exclusively forward such signal units that correspond to acorresponding signal unit in the register. Consequently, the forwardingmeans compares the signal units in question with the signal units beingstored in the register. Only those signal units in question which have acorrespondence in the register are forwarded by the forwarding means.The forwarding means may thus comprise a comparator unit being arrangedto compare the separated and selected signal units with said signalunits in the register. According to a preferred embodiment of theinvention, said unique identification is arranged to make possible saidcomparison. The blocking of signal units in the forwarding means iseffected electronically and may be accomplished by different means. Thesignal units may also contain or be associated with time information,whereby a temporary availability is made possible. By indicating a startpoint in time and a possible end point in time, the signal units may beallowed to pass through the forwarding means during the interval beingdefined between these points in time. However, the signal units inquestion are blocked at any other time.

The register in the registering means is an active register in which itis possible to erase stored signal units and to add further signalunits. Moreover, said register is arranged such that it is possible toeffect said erasure and said addition over a communications system. Onepossibility is to realise said erasure and said addition via atelecommunications network, whereby the arrangement may include a modem.The arrangement thus has a unique address for said communication, whichmay be encrypted. It is also possible that said erasure and saidaddition takes place via, for instance, a satellite channel or a cablenetwork. A secret code may be sent under an encrypted format inconnection with said erasure and said addition, whereby the secret codeis necessary for said erasure respective said addition of signal units.The erasure and the addition, of course, also involves altering ofsignal units. According to an embodiment of the invention, the secretcode is changed periodically in order to ensure the security of thesystem. The central computer includes a register over those uniqueaddresses respective codes that represent authorised users in thesystem.

According to an additional embodiment of the invention, the arrangementincludes a selecting means being arranged to separate and select thereceived signal units from one another. This may be accomplished byfiltering. The selection means may include one or more filters, forinstance, one filter for each frequency or frequency band which shouldbe separated and selected.

According to an additional embodiment of the invention, at least one ofsaid signal units includes at least two signals, whereby said selectingmeans is arranged to separate and select said signals in said signalunit. Said signals may be a video signal and an audio signal of aspecific TV-channel, whereby said selecting means may be arranged toseparate and select said video signal and audio signal. It is therebypossible to exclusively have the video signal forwarded by saidforwarding means, whereby said receiver, i.e. in this case theTV-receiver, exclusively receives the video signal and thus a user onlyhas a possibility to reproduce the image in said TV-channel.

According to an additional embodiment of the invention, the arrangementincludes an identifying means for detecting the incoming signal andprovide at least each signal unit with a unique identification.Preferably, said unique identification includes a digitalidentification, whereby the identifying means is arranged to superimposethe digital identification onto the respective signal unit. If thesignal unit in question includes a video signal and an audio signal,said identifying means may be arranged to provide both said signals witha respective digital identification that is superimposed onto the signalin question. This identification may be allocated initially attransmission of a respective signal unit, via for example a cableTV-network or a satellite link. The identification may includeinformation pertaining to, for instance, signal type and frequency.

According to an additional embodiment of the invention, the arrangementincludes a verification means, which comprises a memory unit for storingthose signal units to which said receiver has authorised access andwhich is arranged to verify that the signals being forwarded by saidforwarding means correspond to a corresponding signal unit in saidmemory unit, whereby if said forwarded signal units do not correspond toa corresponding signal unit in the memory unit the particular signalunit is being registered by means of a specific signal in a registeringunit. The operation of said verification unit is thus to investigatewhether signal units leave the arrangement to which said receiver doesnot have authorised access, i.e. the verification unit checks thereliability of said forwarding means. The verification means is notarranged to block the signal units in question that do not have acorrespondence in said memory, however said signal units are stored insaid registering unit. Said verification means may be arranged such thatall signal units that pass the arrangement are registered in theregistering unit, whereby those signal units that pass said arrangementand are not found in said memory unit are registered together withcertain additional information. These events may, for instance, beregistered in the form of a log along with date and time information.Furthermore, text-TV-pages that are presented in the receiver may beregistered together with page number and time of presentation (date andtime).

According to an additional embodiment of the invention, said signalunits in the registering unit are formatted to be transmitted to acentral computer. Said transmission may be effected according to variousmeans, whereby one possibility is that it takes place over a telephoneline, whereby the arrangement may include a modem. The arrangementincludes a computer, whereby a control unit in the computer may bearranged such that the stored data in said registering unit aretransmitted to said central computer according to certain timeintervals, for instance once per day. In case said arrangement isarranged between a TV-receiver antenna and a TV-receiver it is thuspossible to verify, by means of said central computer, whether a signalunit to which said TV-receiver does not have authorised access isnevertheless received by said TV-receiver. A software in said computercontrols the registration of signal units in said registering unit. Thecentral computer may re-configure the software in said computer, forinstance, by remote upgrading of the arrangement. The central computermay also control said time intervals for transmission and the extent ofthe registered information that is being transmitted.

In connection with satellite reception of TV-signals (or other receptionwhere an external decoder is being utilised), i.e. signal units, in homeenvironments it is possible to, by means of the inventive arrangement,register for example viewer habits. By having the verification meansarranged such that all signal units that pass the verification means areregistered in the registering unit with time and date, viewer surveys,statistical investigations etc are made possible. The central computerincludes software for receiving and processing such registrations in adesired manner. Furthermore, multiple users may be registered for oneand the same arrangement. Each individual then logs in to thearrangement, for instance, by entering a unique code via a remotecontrol, by means of voice recognition, a finger print or eye control.

According to an additional embodiment of the invention, said receiverincludes one of a TV-receiver, a satellite receiver and a radioreceiver. By radio receiver is understood a receiver being used forwireless communication, for instance a mobile telephone.

According to an additional embodiment of the invention, the arrangementis connected to an interface unit via which information may be exchangedwith the central computer over at least one communications network. Thisnetwork may communicate according to arbitrary standard and utiliseanyone of the access technologies known today.

According to an additional embodiment of the invention, the arrangementis connected to a switch, which is arranged to automatically select aninterface in the interface unit that is adapted to at least one of thecommunications networks.

According to an additional embodiment of the invention, the arrangementis connected to a picture telephone unit through which a signal beingspecifically directed to the receiver can be received and a locallyrecorded video signal can be returned such that a picture telephone linkcan be established between the user and at least one other user.

According to an additional embodiment of the invention, the arrangementis included in a subscriber unit, which in turn includes a GPS receiver.The GPS receiver is arranged to convey positional information to thecentral computer. The positional information may constitute a basis forwhich signal units that are forwarded to the receiver respective areblocked by the forwarding means. Typically, the positional informationcan be utilised for graphical presentation of subscriber data to theoperator, for instance, on a map where each subscriber is represented byhis/her graphical position. Information and statistics pertaining to aspecific user can be presented on the map in connection with his/hergeographical position by means of a digital graphical interface.

The positional information also gives the central computer a possibilityto determine whether the subscriber unit has been repositioned andpossibly thereby also by other means been modified in an unauthorisedway.

According to an additional embodiment of the invention, a uniqueidentity is linked to the registering means. On basis of this identitysignal units may either be forwarded or blocked by the forwarding means,such that the signal units only reach the specific users, which areindicated by the unique identity.

Depending on which type of signal units that have been received by thearrangement according to the invention and the signal processing thathas been performed in the arrangement according to the invention, it maybe necessary to further process the forwarded signal units beforetransferring them to the intended receiver.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is now to be explained by means of an exemplaryembodiment and with reference to the attached drawing, of which

FIG. 1 shows how the arrangement is arranged between a TV-receiverantenna and a TV-receiver, and how a central computer is connected tothe arrangement,

FIG. 2 shows parts of the arrangement according to FIG. 1 and how thesignals are led through the arrangement,

FIG. 3 shows a generalisation of the arrangement according to FIG. 1,

FIG. 4 shows an exemplifying system, which includes receivers that areconnected via the proposed arrangement, and

FIG. 5 shows an embodiment, where the proposed arrangement is includedin a subscriber unit having extended communication possibilities.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

FIG. 1 shows how an arrangement 1 according to the invention is arrangedbetween a TV-receiver antenna 2 and a TV-receiver 3 in a TV-set 4. TheTV-set 4 may be of conventional type and includes a screen 5 and theequipment necessary for i.a. the image- and sound reproduction. Thearrangement 1 makes it possible to block signal units to which theTV-receiver does not have authorised access. It should be noted that anarrangement according to the invention may be arranged in connectionwith different types of receivers, such as satellite receivers, radioreceivers etc. Furthermore, it should be noted that the arrangement 1 ispreferably located such that a TV-viewer who uses the TV-set 4 isunaware of the arrangement's 1 existence.

The arrangement 1 includes a computer. Moreover, it is possible tocommunicate with said arrangement 1 from, for instance, a centralcomputer 6 via e.g. a telephone line 7 which is made possible by meansof a modem 8. The power supply of said arrangement 1 can be accomplishedby various means and will not be further mentioned in this application.

The arrangement 1 includes a receiver means 9, a selecting means 10, anidentifying means 11, a forwarding means 12, a registering means 13, averification means 14 and a post processing means 15 as shown in FIG. 2.The function of the receiving means 9, the selecting means 10, theidentifying means 11, the forwarding means 12, the registering means 13,the verification means 14 and the post processing means 15 will bedescribed in further detail in connection with the description of howthe signal units are led through the arrangement 1.

The TV-signals, i.e. the different TV-channels, may reach theTV-receiver 3 via, for instance, terrestrial transmitters, cablenetworks or satellites. The different TV-channels include, for example,an image signal, a so-called video signal and one or more sound signals,so-called audio signals and usually a text-TV-signal. All signals aremodulated onto a carrier wave. When the different signal units, i.e. theTV-channels, reach the arrangement 1 they are received by thearrangement's 1 receiver means 9. In the receiver means 9, whichincludes a receiver, the different signals in the signal unit inquestion, i.e. TV-channels, are converted to baseband. After that, thesignal units in question reach the selecting means 10 that is arrangedto separate and select the signal units in question from one another.This is accomplished by filtering. The selecting means 10 may compriseone or more filters, for instance, one filter for each frequency bandwhich should be separated and selected. In a following step the selectedsignal units reach the identifying means 11, which is arranged to detecta signal type and depending on the signal type allocate a uniqueidentification to the selected signal unit in question, for instance, inthe form of a digital identification being superimposed onto the signalunit in question. This identification may be allocated initially at thetransmission of the respective signal units, via for instance, a cableTV-network or a satellite link.

The signal units in question, that include the digital identification,reach the forwarding means 12 in a next step. The forwarding means 12includes a comparator unit 16 being arranged to compare the separatedsignal units in question with the contents of a register 17 in theregistering means 13. The register 17 includes those signal units thatthe TV-receiver 3 has authorised access to. Only the signal units inquestion that have a correspondence in the register 17 are forwarded bythe forwarding means 12.

After this, the forwarded signal units reach the verification means 14.The verification means 14 includes a memory unit 18, which in similaritywith the registering means 13 includes those signal units to which theTV-receiver 3 has authorised access. If the signal units that are beingforwarded by the forwarding means 12 do not have a correspondence in thememory unit 18, these signal units will be stored along with a warningsignal in a register unit 19 in the arrangement 1. Before the forwardedsignal units leave the arrangement 1 the signal units are processed inthe post processing means 15 with respect to the TV-receiver 3.

The registering means 13 is furthermore allocated a unique identity inthe form of an ID-number and an ID-code. The unique identity offers apossibility to arrange, group or categorise users in different ways. Forinstance, it is possible to based on the unique identity and dataconcerning the user, such as age, sex, civil status or occupation, sendsignal units to the user that are specifically directed to users thatfulfil certain criteria, such as being male and within a particular ageinterval. The software in the central computer includes means forprocessing statistical data pertaining to the users plus means forpresenting the data to the operator via, for instance, a graphicalinterface.

Moreover, an international employer or other larger organisation mayconvey signals to a very specific and well-defined target group byutilisation of these unique identities. All the arrangements whose IDnumbers are included in a listing in the central computer overauthorised receivers may receive the transmitted signal units, while allother arrangements block the signal. Alternatively, ID-numbers may beallocated according to a geographical plan such that ID-numbers within aparticular interval correspond to users within a given geographical area(a country, a city, a region etc.). It is thereby possible to receivecertain signal units selectively within given geographical areas, whichcan be utilised, for instance, by film distributors in order to avoidcollision with other media in other regions, such as cinemas. Moreover,data to be presented via a map image can be generated. This map imagemay, for instance, relate statistics and viewer habits to differentgeographical areas.

According to another embodiment of the invention, the transmission ofthe signal units is accomplished via the Internet in the form ofWeb-TV/Internet-TV (for instance via the Philips product CleverCast PC),whereby the ID-number is linked to a particular IP-address. By utilisingthis embodiment the arrangement's user is provided access to theInternet, whereby the user, for instance, may connect to various homepages.

It should be noted that the memory unit 18 may be left out, whereby theverification unit 14 is arranged to compare those signal units that passthe verification unit 14 with the signal units that are registered inthe register 17 in the registering means 13. According to anotherembodiment of the invention, the verification means 14 may be locatedoutside the arrangement 1, whereby the order between the post processingmeans 15 and the verification means 14 is reversed in relation to whatis shown in FIG. 1.

The arrangement 1 may, for instance, be placed centrally in a block offlats, while the verification means 14 may be located in directproximity to the respective users' TV-receivers 3.

The arrangement 1 includes a control unit 20 that is arranged such thatdata being stored in the register unit 19 is transferred to the centralcomputer 6 at particular time intervals.

The central computer 6 may erase or add signal units to the register 17in the registering means 13 and in the memory unit 18 of theverification means 14 by means of the control unit 20. All suchalterations are stored in the register unit 19 together with time- anddate information, whereby it is possible verify from the centralcomputer 6 that the intended changes have in fact been effected as wellas when this took place.

According to an alternative embodiment of the invention, the controlunit 20 may be arranged to replace certain received signal units withgiven other pre-determined signal units in the form of audio- and/orimage sequences. This is controlled by time indications being associatedto the signal units or by means of special control pulses being sentout.

Irrespective of whether the verification unit 14 is localised internallyor externally relative the arrangement 1, the registered information isforwarded to the central computer 6, either via the arrangement 1 or viaa separate modem.

In the embodiment shown in FIG. 1 the arrangement 1 according to theinvention is connected with a central computer 6 via a modem 8 and atelephone line 7. Naturally, it is also possible to establish aconnection between the arrangement 1 and the central computer 6 by meansof other transmission media than telephone lines. In fact, a channel forthis communication may be set up over arbitrary network or combinationof networks via which an information exchange between the arrangement 1and the central computer 6 can be accomplished. FIG. 3 shows ageneralisation of the assembly in FIG. 1, where the arrangement 1 isconnected to a receiver antenna 2 for reception of signal units, such asdata-, radio- or TV-signals. Furthermore, the arrangement 1 is connectedto a receiver 3 for reproduction of the signals that have been receivedvia the receiver antenna 2. Thus, the receiver 3 is typically a radio-or a TV-receiver, however it can naturally include an arbitrary numberof other alternative decoders for different types of signals. Instead ofthe modem 8, the arrangement 1 communicates with the central computer 6via an interface unit 8 a, which is adapted to at least one interfacebesides PSTN, i.e. the regular telecommunications network for voicetelephony (PSTN=Public Switched Telephone Network). The interface unit 8a may thus be adapted to direct communication over the Internet, viaPLMN (PLMN=Public Land Mobile Network), the electric power network, bymeans of a satellite link or via an equivalent public or privatecommunications network. This is illustrated in FIG. 3. by means of ageneral network 7 a. The central computer 6 is also directly, orindirectly via one or more other networks, connected to the generalnetwork 7 a. Information may thereby be exchanged between thearrangement 1 and the central computer 6.

FIG. 4. shows an example of a system, which includes subscriber units41, 42 respective 43 that each comprises a receiver antenna 2, anarrangement 1, a receiver 3 and an interface unit 8 a according to whathas been described with reference to FIG. 3 above. A satellitetransmitter 44 in the system transmits signal units via a satellite 45,which preferably is positioned in a geostationary orbit around theearth. The receiver antenna 2 in the respective subscriber unit 41-43 isadapted to receive the signal units that are forwarded by the satellite45. According to a preferred embodiment of the invention, the satellitetransmitter 44 is directly, or indirectly, connected to a centralcomputer 6, such that this computer can be updated with respect to whichsignal units (typically channels, programs or data signals) that aresent out. Possibly, the central computer 6 is also given a possibilityto control the transmission of signal units from the satellitetransmitter via this connection. According to the illustrated example, afirst subscriber unit 41 is attached to the central computer 6 via PSTN71 a, a second subscriber unit 42 communicates with central computer 6at least partially over the Internet 72 a and a third subscriber unit 43exchanges information with the central computer 6 at least partly via aPLMN 73 a. This PLMN may be constituted by a mobile communicationsnetwork of arbitrary standard and access technology. It may, forinstance, be a GSM-network (Global System for Mobile communication), aTDMA-network (Time Division Multiple Access), a CDMA-network (CodeDivision Multiple Access) or a W-CDMA-network (Wideband-CDMA). Thearrangement 1 is preferably controlled from the central computer 6 bymeans of control signals being transferred via the satellite system incase of satellite reception of signal units.

FIG. 5. shows an embodiment, where the proposed arrangement 1 isincluded in a subscriber unit 50 having extended communicationpossibilities. Besides the arrangement 1 a GPS-receiver 52 (GPS=GlobalPositioning System) is included in the subscriber unit 50. Furthermore,the subscriber unit 50 includes a switch 53 for effecting an automaticchoice of interface towards the central computer.

The GPS-receiver 52 registers the subscriber unit's 50 geographicalposition and thereby gives an indirect indication of the position of thereceiver(s), which is(are) connected to the subscriber unit 50. Thepositional information may be utilised for controlling transmission ofsignal units within given geographical areas, such as a specificcountry, a specific city etc. An operator can thereby be ensured that aparticular program or a particular channel cannot be received outsidethe desired area of distribution. A map may be used to graphicallyillustrate where the subscribers are located geographically. Eachsubscriber is here represented via a mark on the map and by activationof a specific subscriber's mark (for instance by means of an electronicpointer means, such as a computer mouse) information and statisticspertaining to the subscriber are presented.

The positional information may moreover be utilised by the centralcomputer in order to determine whether the subscriber unit 50 has beenrepositioned from its original location and perhaps thereby also beenmodified or transferred to another user. An updated positionalinformation is sent out at regular intervals, via the switch 53 and aninterface unit 8 a, over a communications network to the centralcomputer. If the positional information would indicate a repositioningof a particular subscriber unit 50, the central computer preferablysends out a command to the registering means 13 in the arrangement 1 inthis subscriber unit 50, which (if the operator so desires) may resultin that the selecting means henceforth will block all received signalunits.

According to a preferred embodiment of the invention, the centralcomputer sends a page signal to the subscriber in connection with theeffecting of such blocking. Typically, the page signal is sent out tothe subscriber (with the particular ID-number) a time period before themoment when all received signal units are actually blocked, such thatthe subscriber is given an opportunity to object against the blockingbeing effected.

The GPS-receiver 52 may in additionally be used for automatic setting ofa time reference (such as a clock) in the arrangement 1.

The picture telephone unit 51 has an input for connection to a localvideo signal, from for instance a picture telephone or a video camera. Apicture telephone signal may thereby be reproduced in a TV-receiverbeing connected to the subscriber unit 50. A sensor 21 in thearrangement 1 detects whether a local video signal is present on thepicture telephone unit's 51 input. If this is the case, the control unit20 connects this signal to the receiving means 9 for furthertransmission through the arrangement 1. Given that the subscriber has apicture telephone subscription with the operator the signal may pass theforwarding means in the arrangement 1 to the TV-receiver 3. The picturetelephone image may either be shown separately across the entire screen5 of TV-receiver 3 or be presented in parallel with other pictorialinformation in the form of, for instance, an image segment within alarger image. According to alternative embodiments of the invention,only one of the sound- and the image information is forwarded to theuser's receiver.

Any communication between the arrangement 1 and the central computer isaccomplished via the switch 53 and the interface unit 8 a. The latterhas, according to a preferred embodiment of the invention, at least twoalternative interfaces for communication via at least two differentcommunications networks. The subscriber unit 50 may therebyalternatively be connected to a first or at least one secondcommunications network. As an alternative, the subscriber unit 50 may besimultaneously connected to at least two communications networks, suchthat if a connection via a primary network is broken, a connection maybe established via at least one secondary network. The switch 53 detectswhich network(s) that is (are) connected to the interface unit 8 a andautomatically controls the connection to these networks according to apre-determined procedure.

The present invention is not restricted to the described embodiments,but may be varied freely within the scope of the following claims.

That which is claimed is:
 1. A subscriber unit for receiving andtransmitting signal information in a communication system, comprising:at least one receiver configured to receive a number of signals within afrequency range, wherein each signal unit of the number of signal unitsrepresents at least one of the following: a data signal, a text-tvsignal, an audio signal, a video signal, or any combination thereof ; atleast one camera is connected to the subscriber unit, a sensor in thesubscriber unit is configured to detect the signals, whereby a controlunit connects this signal to the receiving unit.
 2. Subscriber unitaccording to claim 1, characterized in that said signal units include atleast one of a time information and a secret code.
 3. Subscriber unitaccording to claim 1, only one of the data signal, the text-tv signal,the audio signal, the video signal, or any combination thereof isforwarded to the receiver unit
 4. Subscriber unit according to claim 1,characterized in that a unique identification includes at least adigital identification, whereby said digital identification includesidentifying information pertaining to at least a time information, asecret code, signal type or frequency.
 5. Subscriber unit according toclaim 1, characterized in that at least one of said signal unitsincludes at least two signals wherein one of said signals includes avideo signal and that the other signal includes an audio signal and thatsaid identifying unit is configured to provide said signals in saidsignal unit with said unique identification that is superimposed ontothe respective signal.
 6. Subscriber unit according to claim 4,characterized in that said identifying unit is configured to detect adigital identification of said signals or each signal unit. 7.Subscriber unit according to claim 1, characterized in that a registerincludes at least those signal units to which said addressed receiverhas authorized access, whereby said comparator unit is furtherconfigured to exclusively forward such signal units that correspond to acorresponding stored signal unit in said register.
 8. Subscriber unitaccording to claim 7, characterized in that said register is an activeregister in which it is possible to erase stored signal units and addfurther signal units, and where said register is arranged such that saiderasure and addition can be affected via a communications system. 9.Subscriber unit according to claim 7, characterized in that the uniqueidentity is linked to the register which is configured to include atleast one of an ID-number and an ID-address, whereby said uniqueidentity forming a basis for which signal units that are being forwardedor blocked by the comparator unit.
 10. Subscriber unit according toclaim 1, characterized in that said comparator unit is configured tocompare the signal units with said signal units in said register,whereby at least one of said unique identification and digitalidentification is arranged to make possible said comparison. 11.Subscriber unit according to claim 1, characterized in that averification unit is configured to verify said signal units beingforwarded by said comparator unit.
 12. Subscriber unit according toclaim 1, characterized in that it is connected to a picture telephoneunit through which a picture telephone link is established between auser and at least one other user.
 13. Subscriber unit according to claim1, characterized in that said subscriber unit, comprises a positionalinformation receiver, whereby the positional information forms a basisfor which signal units that are being forwarded or blocked by thecomparator unit.
 14. Subscriber unit according to claim 1, characterizedin that said receiver comprises at least one of a TV-receiver, asatellite receiver and a radio receiver.
 15. Subscriber unit accordingto claim 1, characterized in that it is connected to an interface unitthrough which information can be exchanged with a central computer overat least one communications network.
 16. Subscriber unit according toclaim 15, characterized in that it is connected to a switch, which isarranged to automatically select an interface in the interface unit thatis adapted to at least one of the communications networks. 17.Subscriber unit according to claim 15, characterized in that the centralcomputer is arranged to include data pertaining to at least one of aunique identity, a unique identification, an ID-number, an ID-addressand a unique address, which represents at least a subscriber, wherebysaid data forms a basis for said central computer to verify whether saidreceiver is authorized to forward said signal units.
 18. Subscriber unitaccording to claim 15, characterized in that the central computer isarranged to include data pertaining to at least one of a uniqueidentity, a unique identification, an ID-number, an ID-address and aunique address, which represents at least a subscriber, whereby saiddata forming a basis for said central computer to process said datapertaining to each users viewer surveys and statistical investigation.